arXiv subjects

Alexei V. Khomenko

Publications and source records attributed to Alexei V. Khomenko.

4 recordsLinked to original sources

arXiv2014

Self-organization of adatom adsorption structure at interaction with tip of dynamic force microscope

The formation of an adatom adsorption structure in dynamic force microscopy experiment is shown as a result of the spontaneous appearance of shear strain caused by external supercritical heating. This transition is described by the Kelvin-Voigt equation for a viscoelastic medium, the relaxation Landau-Khalatnikov equation for shear stress, and the relaxation equation for temperature. It is shown that these equations formally coincide with the synergetic Lorenz system, where the shear strain acts as the order parameter, the conjugate field is reduced to the stress, and the temperature is the control parameter. Within the adiabatic approximation, the steady-state values of these quantities are found. Taking into account the sample shear modulus vs strain dependence, the formation of the adatom adsorption configuration is described as the first-order transition. The critical temperature of the tip linearly increases with the growth of the effective value of the sample shear modulus and decreases with the growth of its typical value.

cond-mat.mtrl-sci↗

arXiv2010

Study of friction of Ag and Ni nanoparticles: an atomistic approach

Manipulation of metal nanoparticles using atomic force microscope is a promising new technique for probing tribological properties at the nanoscale. In spite of some advancements in experimental investigations, there is no unambiguous theoretical treatment of processes accompanying the movement of metallic nanoislands adsorbed on a flat surface and additional research is required. In this paper, we describe computer experiments based on classical molecular dynamics in which the behavior of silver and nickel nanoparticles interacting with a graphene sheet and sheared with constant force is studied. Frictional force acting on the nanoislands is measured as a function of their size. It is shown that its average value grows approximately linearly with contact area, and slopes of linear fits are close to the experimentally observable ones. The dependence of the friction force value and of the shape of the measured friction curves on the type of metal atom is revealed and its possible reasons originating from atomistic background are discussed.

cond-mat.mes-hall↗

arXiv2004

Noise influence on solid-liquid transition of ultrathin lubricant film

The melting of ultrathin lubricant film by friction between atomically flat surfaces is studied. The additive noises of the elastic shear stress and strain, and the temperature are introduced for building a phase diagram with the domains of sliding, stick-slip, and dry friction. It is shown that increase of the strain noise intensity causes the lubricant film melting even at low temperatures of the friction surfaces.

cond-mat.stat-mech↗

arXiv2000

Field theory of avalanche formation

Self-organizing system is studied whose behavior is governed by field of an order parameter, a fluctuation amplitude of conjugate field and a couple of Grassmannian conjugated fields that define the entropy as a control parameter. Within the framework of self-consistent approach the dependencies of macro- and microscopic susceptibilities as well as memory and nonergodicity parameters are determined as a functions of the intensities of thermal and quenched disorders. Making use of the sandpile model shows that proposed scheme determines the conditions of avalanches formation in self-organized criticality phenomena.

cond-mat.stat-mech↗